2017/10/02 by Guang Bian, Bian, Guang, Tay‐Rong Chang +9
Physics and Astronomy · Engineering · Materials Science · #Photorefractive and Nonlinear Optics #Terahertz technology and applications #Quasicrystal Structures and Properties
paper · pdf · doi:10.48550/arxiv.1710.00908
Bismuth has been the key element in the discovery and development of topological insulator materials. Previous theoretical studies indicated that Bi is topologically trivial and it can transform into the topological phase by alloying with Sb. However, recent high-resolution angle-resolved photoemission spectroscopy (ARPES) measurements strongly suggested a topological band structure in pure Bi. To address this issue, we study the band structure of Bi and Sb films by ARPES and first-principles calculations. By tuning tight binding parameters, we show that Bi quantum films in topologically trivial and nontrivial phases response differently to surface perturbations. Therefore, we establish an experimental route for detecting the band topology of Bi by spectroscopic methods. In addition, our circular dichroic photoemission illuminates the rich surface states and complex spin texture of the Bi(111) surface.